Second-look surgery for colorectal cancer. The second time around

Eighty-six colorectal cancer patients who entered the Radioimmunoguided Surgery (RIGS) protocol study were evaluated for 2-, 3-, 4-, and 5-year survival following second-look surgical procedures. Strict preoperative evaluation criteria eliminated patients with extra-abdominal tumor involvement. A saturated potassium iodide preparation was given before the intravenous administration of the B72.3 monoclonal antibody (1 mg) radiolabeled with 2 mCi of iodine-125 by the IODOGEN method. Precordial monitoring of the biologic clearance by the handheld, gamma-detecting probe (Neoprobe 1000 instrument) was conducted at weekly intervals until the average count was less than 20 counts in 2 seconds. Once the drug cleared from the blood, surgery was performed. The mean time interval between injection and operation was 24 days, with a range of 21 to 28 days and a median of 23 days. At surgery the abdomen was explored through the traditional methods of palpation and inspection, and the surgeon committed to a planned procedure. The abdomen was then re-explored with the handheld, gamma-detecting probe and the surgeon stated another intraoperative assessment. After using both traditional and RIGS detection methods, the surgeon stated whether his or her surgical plans changed because of the additional intraoperative information provided by the RIGS system. Fifty-three patients (62%) were deemed resectable by the traditional methods of palpation and inspection, but only 40 (47%) were specified as resectable by RIGS exploration. Two-, three-, four-, and five-year survival data could be gathered for each of the three groups: RIGS resectable (n = 40), traditional nonresectable (n = 33), and RIGS nonresectable (n = 13). At 2 years 95% of the resectable, 36% of the traditional nonresectable, and 53% of RIGS nonresectable patients survived. At 3 years 83%, 7%, and 30% of these patients survived, respectively. For the resectable patients, 74% survived at 4 years and 60% at 5 years, with no survivors from either nonresectable group. Use of the RIGS system increased accurate selection of resectable patients undergoing second-look surgery for recurrent colorectal cancer.

Second hepatic resection for metastatic colorectal cancer

We report a case where repeat hepatic resection was successfully performed 3 years after extended right hepatic lobectomy for metastatic colorectal cancer. The patient remains well and disease free 2.5 years after the second hepatic resection.

Impact of Radioimmunoguided Surgery

Radioimmunoguided surgery (RIGS) is a technique employed to locate tumor deposits with the aid of intravenously injected, tumor-specific, radiolabeled monoclonal antibodies and a small gamma detecting device. The gamma detecting probe (GDP) is a small, portable unit which has the capacity to be used intraoperatively to survey the entire peritoneal surface for increased radioactivity indicative of targeted tumor tissue during abdominal exploration for colorectal cancer. Trials in humans have demonstrated the ability of this system to locate clinically nonpalpable tumor deposits in patients undergoing carcinoembryonic antigen second-look laparotomies. This feature may be of value in improving the definition of tumor location and extent as well as allowing a more thorough resection of tumor-bearing tissue to be performed and hopefully improving overall patient survival.

Radioimmunoguided surgery using iodine 125 B72.3 in patients with colorectal cancer

Preliminary data using B72.3 murine monoclonal antibody labeled with iodine 125 suggested that both clinically apparent as well as occult sites of colorectal cancer could be identified intraoperatively using a hand-held gamma detecting probe. We report the preliminary data of a multicenter trial of this approach in patients with primary or recurrent colorectal cancer. One hundred four patients with primary, suspected, or known recurrent colorectal cancer received an intravenous infusion of 1 mg of B72.3 monoclonal antibody radiolabeled with 7.4 x 10 Bq of iodine 125. Twenty-six patients with primary colorectal cancer and 72 patients with recurrent colorectal cancer were examined. Using the gamma detecting probe, 78% of the patients had localization of the antibody in their tumor; this included 75% of primary tumor sites and 63% of all recurrent tumor sites; 9.2% of all tumor sites identified represented occult sites detected only with the gamma detecting probe. The overall sensitivity was 77% and a predictive value of a positive detection was 78%. A total of 30 occult sites in 26 patients were identified. In patients with recurrent cancer, the antibody study provided unique data that precluded resection in 10 patients, and in another eight patients it extended the potentially curative procedure.

Applications of monoclonal antibodies and recombinant cytokines for the treatment of human colorectal and other carcinomas

Monoclonal antibodies (MAbs) which recognize a human tumor antigen, termed tumor-associated glycoprotein-72 (TAG-72), have successfully been used to localize primary as well as metastatic colorectal tumor lesions in patients. The localization of the anti-TAG-72 MAbs has also been exploited intraoperatively using a hand-held gamma probe. That procedure, termed radioimmunoguided surgery (RIGS), has identified occult tumors which were not detected using standard external imaging techniques. In another clinical trial, interferon-gamma (IFN-gamma) was administered intraperitoneally to patients diagnosed with either gastrointestinal or ovarian carcinoma with secondary ascites. Analysis of the tumor cells isolated from the malignant ascites revealed a substantial increase in TAG-72 expression on the surface of tumor cells isolated from seven of eight patients. The results provide evidence that the combination of an anti-carcinoma MAb with the administration of a cytokine, such as IFN-gamma, may be an effective approach for the detection and subsequent treatment, of colorectal carcinoma.

Gamma-detecting probe and autoradiographic studies of radiolabeled antibody B72.3 in CX-1 colon xenografts

Nude mice bearing CX-1 colon tumors were injected with 50 microCi 125I-labeled monoclonal antibody (MAb) B72.3. Radioactivity in tumors was studied with the gamma detecting probe (GDP) on days 1, 3, 7, and 10 after MAb injection. On each day, two mice were sacrificed and sections were examined with autoradiography (ARG), immunoperoxidase methods (IMP), and routine stains. Mean probe counts showed increasing tumor to background ratios and ARG demonstrated a progressive increase in radionuclide in the tumors. The distribution of 125I was primarily around the vascular spaces on day 1, but by day 3 and progressively it appeared in tumor gland lumina and necrotic areas. A regional correlation was shown between radionuclide in vascular spaces and its sequestration in tumor elements.

Confusion in the terminally ill: recognition and management

Pain has been managed aggressively by hospice programs. However, other problems, particularly neuropsychiatric problems, such as confusion, can go unrecognized and untreated even in a hospice setting. The resulting disturbing, violent or disruptive behavior will severely detract from the quality of life the patient and family can share together. Dementia and delirium can be diagnosed using a mental status exam. Care-givers can then be informed about the special needs of the patients and prepared for potential problems. Identification of reversible causes for delirium can continue while agitated behavior is managed with behavioral and pharmacologic approaches. Confusion is a common problem in the terminally ill and prompt recognition and management of the potentially disruptive symptom can do a great deal to maximize the quality of the patient's life.

Carcinoembryonic antigen directed multiple surgical procedures for recurrent colon cancer confined to the liver

During the past 14 years, eight patients have undergone two or more major hepatic procedures in an attempt to control metastatic colon cancer confined to the liver. A total of 19 operations was performed. In all cases, a rising level of carcinoembryonic antigen was the main indicator for surgical intervention. There were no operative deaths. Major complications occurred in 15 per cent. Following the first hepatic intervention, two patients remain alive and free of disease at 43 and 47 months (56 and 100 months since diagnosis), respectively. In the six patients who have died, survival from the first hepatic intervention ranged from 17 to 38 months (median 27 months). Age, sex, location of primary, size of primary, interval from primary operation to second operation, and site of hepatic metastasis did not influence survival. In carefully selected patients with metastatic colon carcinoma confined to the liver, encouraging results can be obtained by performing multiple surgical procedures.

The impact of radioimmunoguided surgery (RIGS) on surgical decision-making in colorectal cancer

Radioimmunoguided surgery (RIGS system) was performed in ten patients with rectal or low sigmoid colon carcinoma with the use of a hand-held gamma detector (Neoprobe 1000) intraoperatively and externally after injection of radiolabeled (125I) monoclonal antibody to detect pelvic and metastatic tumor. Fifteen procedures, including six exploratory laparotomies, four transperineal explorations, two transsacral explorations, one transvaginal biopsy, one brachytherapy, and one transanal polypectomy, were performed. Two patients had previous low anterior resection, seven abdominoperineal resection, and one a rectal polypectomy. Five patients had previous pelvic radiation therapy. Reoperation was indicated by elevated CEA levels in seven patients (70 percent), persistent pelvic pain in six (60 percent), and a suspicious radiologic study in seven (70 percent). RIGS system localized tumors verified by histopatholoy in all ten patients (100 percent); one patient with a positive CT scan and probe findings lacked histopathologic confirmation on frozen section, but had a tumor confirmed on permanent histology. Five major abdominal operations were avoided; in five patients major modifications were made in the surgical procedure based on probe findings. Six received chemotherapy or radiation therapy based on findings of the RIGS system. In six patients with negative or equivocal CT scans, the RIGS system localized histopathologically confirmed tumor. Major abdominal procedures can be avoided, the surgical approach modified, and other modes of therapy instituted earlier with the use of the RIGS system.

Radioimmunoguided surgery in recurrent colorectal cancer: the role of carcinoembryonic antigen, computerized tomography, and physical examination

From January 1986 to December 1987, 32 patients with recurrent colorectal cancer had second-look radioimmunoguided surgery (RIGS system). All patients had pathologic confirmation of recurrence. The RIGS system identified 81% of recurrences, and in six patients recurrent tumor was identified only by RIGS. All patients had physical examination, carcinoembryonic antigen (CEA) assay, and computerized tomography of the abdomen and pelvis. Detection of recurrence was based on symptoms in six, elevated CEA value in 25, and physical examination in one. The CEA was elevated preoperatively in 30 patients; two false-negative results occurred in symptomatic patients who had pelvic recurrence. The median CEA value in those with liver recurrence was 30 ng/ml (range 5.2 to 298) and for pelvic recurrence 13 ng/ml (range 1.9 to 31) (P less than .05). The overall sensitivity of CT was 41% (abdomen other than liver 37%, liver 56%, and pelvis 22%). The combination of elevated CEA, symptoms, and physical findings identified 100% of recurrences. We conclude that a rising CEA remains the most accurate indicator of recurrence. CT should not be done routinely to detect recurrent colorectal cancer unless CEA is elevated or the patient is symptomatic. In our study the intraoperative use of the RIGS system aided the surgeon in identifying occult tumors.

The use of a hand-held gamma detector improves the safety of isolated limb perfusion

We used two hand-held gamma-detecting probes (GDP) (Neoprobe 1000 system) capable of detecting small gamma emissions to monitor leakage in patients undergoing hyperthermic isolated limb perfusion (HILP) who received 800 microCi Technetium 99m pentetate through the perfusate. The percentage of gamma-ray leakage was calculated by a simultaneous reading of two probes at 1-minute intervals (one over the precordial area and one over the thigh) and this was compared to results of simultaneous blood sampling from the perfusate and systemic circulation at 15-minute intervals for gamma well counting (GWC). The percentage of leakage recorded by the GDPs was essentially identical to that detected by the GWC (7.3% and 8.2%, respectively at the conclusion of the perfusion). The GDP gives an immediate and accurate indication of the percentage of leakage during HILP, making it a safer procedure.

Symptom management in the home-based terminal cancer patient

Comprehensive symptom management is the hallmark of good medical care of the terminally ill cancer patient. Careful attention to patient comfort and early assessment and intervention to alleviate distressing symptoms enable the patient to remain at home, and maximize the quality time which the patient and family can share.

Solving the problem of antibody interference in commercial "sandwich"-type immunoassays of carcinoembryonic antigen

We evaluated the effect of human anti-murine antibodies (HAMA) on apparent concentrations of carcinoembryonic antigen (CEA) as measured in serum with commercial enzyme immunoassay (EIA) kits manufactured by Abbot ("two-step" double monoclonal antibody assay), Roche, and Hybritech (room-temperature protocol). In sera from patients given parenteral murine monoclonal antibody for experimental diagnostic and immunotherapy studies, HAMA titers were determined with Immunomedics' "ImmuSTRIP HAMA-EIA" kit reagents. "True" CEA titers were established by using the ImmuCEA/MA-EIA and heat-extraction to destroy HAMA before assay for CEA. The concordance of the ImmuCEA/MA assay with the Abbott and Roche CEA EIAs was established with sera from normal individuals and from patients who had not received parenteral injections of murine monoclonal antibody. At high (100 mg/L) concentrations of HAMA, false-positive results were observed with all three kits. The Hybritech and Roche assays were more sensitive to interference by HAMA than was the Abbott CEA-EIA, false-positive results being observed at HAMA concentrations between 1 and 10 mg/L. Similar sensitivity of the three kits to interference by primate anti-MAb sera was demonstrated. Use of primate anti-MAb sera to create controls with HAMA activity and of analyte is recommended to evaluate MAb assays for potential HAMA interference and for use to devise methods to eliminate HAMA interference.

Viable intraluminal tumour cells and local/regional tumour growth in experimental colon cancer

To determine if viable intraluminal tumour cells can leak through a watertight anastomosis and cause local/regional (extraluminal) tumour growth, tumour cells were introduced 2 cm proximal to a colonic anastomosis following laparotomy in a Wistar/Furth rat colon cancer model. Local/regional tumour growth was observed in all rats except a sham anastomotic group. No intraluminal tumour growth was observed in either group. Viable intraluminal tumour cells cause local/regional tumour growth by leakage through a clinically intact anastomosis and may be an important cause of local/regional tumour growth in human colorectal cancer.

Solving the problem of antibody interference in commercial "sandwich"-type immunoassays of carcinoembryonic antigen

We evaluated the effect of human anti-murine antibodies (HAMA) on apparent concentrations of carcinoembryonic antigen (CEA) as measured in serum with commercial enzyme immunoassay (EIA) kits manufactured by Abbot ("two-step" double monoclonal antibody assay), Roche, and Hybritech (room-temperature protocol). In sera from patients given parenteral murine monoclonal antibody for experimental diagnostic and immunotherapy studies, HAMA titers were determined with Immunomedics' "ImmuSTRIP HAMA-EIA" kit reagents. "True" CEA titers were established by using the ImmuCEA/MA-EIA and heat-extraction to destroy HAMA before assay for CEA. The concordance of the ImmuCEA/MA assay with the Abbott and Roche CEA EIAs was established with sera from normal individuals and from patients who had not received parenteral injections of murine monoclonal antibody. At high (100 mg/L) concentrations of HAMA, false-positive results were observed with all three kits. The Hybritech and Roche assays were more sensitive to interference by HAMA than was the Abbott CEA-EIA, false-positive results being observed at HAMA concentrations between 1 and 10 mg/L. Similar sensitivity of the three kits to interference by primate anti-MAb sera was demonstrated. Use of primate anti-MAb sera to create controls with HAMA activity and of analyte is recommended to evaluate MAb assays for potential HAMA interference and for use to devise methods to eliminate HAMA interference.

Intra-abdominal recurrence of colorectal cancer detected by radioimmunoguided surgery (RIGS system)

Since 1986, 32 patients with metastatic colorectal cancer have undergone second-look radioimmunoguided surgery (RIGS system). The primary tumor was located in the right and transverse colon in 11 patients, left and sigmoid colon in 16, and rectum in five. The carcinoembryonic antigen level was elevated in 30 patients (94%); all patients underwent a computed tomographic scan of the abdomen and pelvis. The overall sensitivity of the computed tomographic scan was 41% (abdomen other than liver, 27%; liver, 58%; and pelvis, 22%). The RIGS system identified recurrent tumor in 81% of the patients. The most common site of metastasis was the liver (41%), independent of the primary location. Local/regional recurrences alone accounted for 40% of all recurrences. In six patients (18%), recurrent tumor was found only with the RIGS system. The RIGS system is more dependable in localizing clinically obscure metastases than other methods, and carcinoembryonic antigen testing remains the most accurate preoperative method to indicate suspected recurrences.

Radioimmunoguided surgery using monoclonal antibody

The potential proficiency of radioimmunoguided surgery in the intraoperative detection of tumors was assessed using labeled monoclonal antibody B72.3 in 66 patients with tissue-proved tumor. Monoclonal antibody B72.3 was injected 5 to 42 days preoperatively, and the hand-held gamma-detecting probe was used intraoperatively to detect the presence of tumor. Intraoperative probe counts of less than 20 every 2 seconds, or tumor-to-adjacent normal tissue ratios less than 2:1 were considered negative (system failure). Positive probe counts were detected in 5 of 6 patients with primary colon cancer (83 percent), in 31 of 39 patients with recurrent colon cancer (79 percent), in 4 of 5 patients with gastric cancer (80 percent), in 3 of 8 patients with breast cancer (37.5 percent), and in 4 of 8 patients with ovarian cancer (50 percent) undergoing second-look procedures. Additional patients in each group were scored as borderline positive. Overall, radioimmunoguided surgery using B72.3 identified tumors in 47 patients (71.2 percent), bordered on positive in 6 patients (9.1 percent), and failed to identify tumor in 13 patients (19.7 percent). Improved selection of patients for antigen-positive tumors, the use of higher affinity second-generation antibodies, alternate routes of antibody administration, alternate radionuclides, and more sophisticatedly bioengineered antibodies and antibody combinations should all lead to improvements in radioimmunoguided surgery.

Intraoperative radioimmunolocalization of colorectal carcinoma with a hand-held gamma probe and MAb B72.3: comparison of in vivo gamma probe counts with in vitro MAb radiolocalization

A new intraoperative approach to tumor localization using radiolabelled monoclonal antibody (MAb) B72.3 involves the use of a hand-held gamma-detecting probe (GDP) by the surgeon and, subsequently, the pathologist. We report here the use of 125I-labelled MAb B72.3 IgG and a GDP to localize primary and metastatic colorectal cancer in 31 patients. The patients were administered radiolabelled MAb i.v., and all underwent surgical exploration 5 to 35 days post-injection. In vivo localization of the MAb was evaluated using a GDP, with tumor and normal tissue counts being obtained. In each case, the subsequent tumor and normal tissue that were resected were analyzed in vitro for MAb localization; this was evaluated by calculating the radiolocalization index, i.e., the ratio of the injected dose per gram localized to tumor versus that of normal tissue. When the GDP was used intraoperatively, MAb B72.3 localized tumors in 68% (21/31) of the patients; the arbitrary criterion of tumor-to-normal tissue ratios higher than or equal to 2.0:1 in vivo being taken as positive. Resected tumor radiolocalization indices ranged from 0.5 to 543, and 71% (22/31) of the patients studied had tumors with radiolocalization indices higher than or equal to 3. Of 50 carcinoma biopsies, 34 that were probe-positive were antigen-positive when B72.3 was used in immunoperoxidase assays, while 4 carcinoma biopsies that were probe-negative were also antigen-negative. Twelve of 50 biopsies were probe-negative and antigen-positive, but many of these lesions only contained a few antigen-positive cells; none of the 50 was probe-positive and antigen-negative. Tumors of all histologic grades localized injected MAb and, in general, higher in vivo probe ratios and radiolocalization indices were obtained from patients who underwent surgery 20 to 35 days following injection of the MAb. MAb B72.3 localized tumor in all sites to which colon carcinoma commonly metastasizes, including mesenteric and peri-aortic lymph nodes, liver, lung, and peri-rectal soft tissue. There was a strong statistical correlation (p = 0.001) between detecting MAb B72.3 localization to tumors using the GDP intraoperatively and subsequent in vitro analysis of cpm/g for tumor versus normal tissues. These studies thus further validate the use of 125I-labelled MAb B72.3 IgG and of a hand-held gamma probe for the intraoperative detection of carcinomatous lesions.

Use of polar solvents in chemoprevention of 1,2-dimethylhydrazine-induced colon cancer

To examine the effect of the polar solvents on 1,2-dimethylhydrazine (DMH)-induced colon cancer, 100 male Sprague-Dawley rats were randomly allocated to a control and three treatment groups. Treated animals received N-methylformamide (NMF), dimethylsulfoxide (DMSO), or methylsulfonylmethane (MSM) added to drinking water 1 week before carcinogen injections commenced and for the duration of the experiment. Primary tumors were detected by serial laparotomy under ether anesthesia performed at 2-month intervals and commencing after carcinogen injections had been completed. The average time to tumor onset was significantly delayed in rats receiving NMF and MSM (P = 0.0141 and 0.0398 respectively, Mantel-Haenszel test). In addition, fewer poorly differentiated tumors were noted in treatment groups. No weight loss or toxicity was observed. These findings demonstrate that the polar solvents significantly reduce the latent period to tumor onset in DMH-induced colon cancer and indicate the need to further investigate such compounds as chemopreventive agents.

Multiple reoperations in recurrent colorectal carcinoma. An analysis of morbidity, mortality, and survival

Fifty-eight patients in an existing prospective study were evaluated to determine if multiple reoperations for recurrent colorectal carcinoma extended survival. All patients had at least three major operative procedures. The median survival from first, second, third, fourth, and fifth recurrence was 29.9, 17.3, 16, 12.3, and 7.2 months, respectively. The median postoperative hospital stay was 11 days, with a range of 1 to 96 days. The major complication rate was 17%. Twenty-one patients are still alive 19 to 140 months from diagnosis (mean, 50.3 months), 9 to 125 months from the first recurrence (mean, 31.1 months), and 5 to 109 months (mean, 22 months) from the second recurrence. Eleven patients have no evidence of disease. Reoperation for recurrent colorectal carcinoma can be done with acceptable morbidity and mortality and an increase in survival.

Multiple reoperations in recurrent colorectal carcinoma. An analysis of morbidity, mortality, and survival

Fifty-eight patients in an existing prospective study were evaluated to determine if multiple reoperations for recurrent colorectal carcinoma extended survival. All patients had at least three major operative procedures. The median survival from first, second, third, fourth, and fifth recurrence was 29.9, 17.3, 16, 12.3, and 7.2 months, respectively. The median postoperative hospital stay was 11 days, with a range of 1 to 96 days. The major complication rate was 17%. Twenty-one patients are still alive 19 to 140 months from diagnosis (mean, 50.3 months), 9 to 125 months from the first recurrence (mean, 31.1 months), and 5 to 109 months (mean, 22 months) from the second recurrence. Eleven patients have no evidence of disease. Reoperation for recurrent colorectal carcinoma can be done with acceptable morbidity and mortality and an increase in survival.

Reoperation directed by carcinoembryonic antigen level: the importance of a thorough preoperative evaluation

Many asymptomatic patients suspected to have recurrent colorectal cancer based on an elevated carcinoembryonic antigen level will be spared unnecessary operation if strict attention is paid to their preoperative evaluation. Liver and renal function should be assessed. Unresectable extraabdominal and intraabdominal recurrence or metastases should be excluded. Patients being evaluated for recurrence after curative resection of a rectosigmoid cancer should undergo a bone scan. Having satisfactorily ensured normal results for these investigations, the surgeon should then proceed to search for an intraabdominal source of tumor recurrence.